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## DHASHNI 3 years ago sin A ----- = cos A (known) ................(sin 30)/tan 30 ? tan A

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1. sai1234

cos 30=root(3)/2

2. DHASHNI

yeah ,,, which is equal to cos 30

3. DHASHNI

but ,,,,, sin 0/tan 0 is not equal to cos 0 why so?

4. hba

what do we have to find

5. DHASHNI

|dw:1342799783750:dw|

6. DHASHNI

|dw:1342799803525:dw|

7. hba

@DHASHNI it is equal

8. ParthKohli

|dw:1342799811401:dw|

9. ParthKohli

$$\sin \div \cos = \tan$$

10. ParthKohli

$$\sin \div \tan \ne \cos$$

11. Neemo

@hba Ohh ! pleaase ! 0/0 =1 :) !!!!!!

12. ParthKohli

$$\color{Black}{\Rightarrow \tan 0 = \Large {\sin 0 \over \cos0} \normalsize = {0 \over1} = 0}$$

13. ParthKohli

I believe that you are mistaken. sinx/tanx is not equal to cosx.

14. DHASHNI

why its a property

15. ParthKohli

The number '0' spoils it all.

16. Neemo

this property is correct since tan(A)$\tan(A) \neq 0$

17. DHASHNI

tan 0 is 0

18. Neemo

yeaah !

19. ParthKohli

I see that all the exceptions come from the number $$0$$. I like this number. You can do anything from it(prove 2 = 1) ;)

20. DHASHNI

yeah

21. ParthKohli

I believe that we may just conclude that $$\Large {\sin x \over \tan x} \normalsize = \cos x , x \ne 0$$

22. DHASHNI

but this is a property right?

23. ParthKohli

It is.

24. ParthKohli

$$\color{Black}{\theta \ne 0 \Rightarrow {\Large {\sin \theta \over \tan \theta}} = \cos \theta}$$

25. ParthKohli

That was mathematical language.

26. Neemo

@ParthKohli Come on !( 2=1) and yes The property is correct ! for $x \neq k \pi$ $x \neq \pi/2$

27. Neemo

sorry $x \neq \pi/2 +k \pi$ for the second one !

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